Need help building 4th order for 2 soundqubed hds312s

[Jordan Thurston]

I'm looking to build a 4th order for my 2 soundqubed hds312s box is going in the trunk of a 2012 impala looking to have the port firing through the smaller part of my seat that folds down. How much space would I need and what ratio and tuning should I use ? Any help would be appreciated

[Jordan Thurston]

I'm gunna go with a 2:1 ratio and 47 hz tuning and see how it sounds I guess 5 cubes ported and 2.5 sealed or maybe go with 3 sealed instead trying to be able to play like 25 hz to 60hz